Fighter pilots often have seconds to decide whether to open fire, and this month they will train at Camp Atterbury to know how to make that choice.

The post, in southern Johnson County and northeastern Brown County, is hosting a major NATO training exercise involving pilots and soldiers from Germany, Finland, France and 11 other countries. The allies will train on how to avoid shooting at troops who are on their side and use high-tech sensors that allow them to distinguish friend from foe, Navy Capt. Kent Davis said.

Residents who live nearby should expect to hear the roar of fighter jets and the whir of helicopters both day and night when the training exercise starts Thursday, Maj. Lisa Kopczynski said. More aircraft than normal will fly over Camp Atterbury through Sept. 25.

Pilots will practice using radar that warns them not to bomb or shoot at troops from other countries who are assisting in combat or on peacekeeping missions, Davis said. The goal is to prevent friendly fire deaths, such as when an American fighter pilot killed four Canadian soldiers in 2002 by dropping a bomb on them during the Afghanistan war.

The Pentagon has been staging international training exercises for the past decade to train pilots, artillery crews and ground troops on how to identify allies before pulling the trigger.

In past years, the Bold Quest exercise has taken place in Norway, the United Kingdom and several different posts in the United States.

Camp Atterbury is the first National Guard post to host Bold Quest, Davis said.

The Pentagon decided to conduct the event at Camp Atterbury this year partly because it has its own restricted airspace, Brig. Gen. Omer “Clif” Tooley said. The post near Edinburgh increasingly is a hub for large-scale training and the testing of cutting-edge military hardware.

About 500 soldiers from Australia, Belgium and other countries will train at Camp Atterbury and the Muscatatuck Urban Training Complex in Jennings County during the next few weeks.

Transporting, feeding and equipping the troops for the war-games exercise is expected to cost at least $5 million. They’ll stay at Camp Atterbury, where they’ll also fly overhead.

Fighter pilots will respond to simulated requests for air support from coalition troops who come under fire while providing humanitarian assistance.

The pilots have to be careful about returning fire in a populated area and will use a computer system to determine if there are any friendly forces near the target. The technology lets them quickly identify where coalition troops are and if it’s safe to fire, Davis said.

They’ll familiarize themselves with different types of technology, including radar, infrared and radio systems, which show them what side the soldiers on the ground are on. For instance, pilots will train with radios that automatically send challenge and password signals to each other.

Ground troops and pilots don’t have to actually talk to each other on the radio. Instead, the pilot’s radio will instantly determine if the troops are on the same radio system by seeing if it uses the same set of encrypted frequencies.

“A pilot could only have seconds to determine whether to engage a target,” Davis said. “There’s little margin for error, so you need instantaneous information about the battlefield conditions.”

Pilots also will use infrared scanners that recognize markings on vehicles or uniforms of their allies, warning them when to hold fire.

The technology that works best at Camp Atterbury will be shared by NATO counties during ongoing and future missions overseas. All allies need to use the same devices to recognize each other on the battlefield to avoid any friendly fire deaths, Davis said.

ABOUT THE TRAINING

Camp Atterbury will host an international training exercise involving fighter pilots this month.What: The Bold Quest exercise trains international allies on how to avoid friendly fire accidents, such as by testing technologies that identify friendly forces.When: Thursday through Sept. 25What to expect: Aircraft will fly over the post both day and night during the exercise.Participating countries: United States, Australia, Belgium, Canada, Denmark, Finland, France, Germany, Italy, Netherlands, Norway, Spain, Poland and the United Kingdom